Improvement in making zinc-white



J. E. BURROWS.

Making White Zinc.

No. 8,416. Patented Aug. 14. 1855.

AM. PHOTO-LITHILCO. N.Y, (OSBORNE'S PROCESS.)

iINrrnn Srarns Farmer wrrrcag JOHN E. BURROXVS, OF NEXVARK, NEW JERSEY.

IMPROVEMENT lN WlAKlNG ZlNC-Wl-HTE.

Specification forming part of Letters Patent No. ESQ ill] 5, datedAugust 14, 1855.

To aZZ whom it may concern:

Be it known that I, JOHN E. BURROWS, of Newark, Essex county, State ofNew Jersey, have invented a new and useful improvement in furnaces forthe manufacture of white oxide of zinc from ores of zinc andfranklinite; and I do hereby declare the followingto be a fulldescription of the same.

The nature of my invention consists in combining, with a furnace made ofbrick, iron, or other suitable material, a series of perforatedgrate-bars and an air-chamber underneath having a force air-pipeinserted in one side of it for the purpose of forcing a blast of airinto the closed air-chamber to support .the combustion of thecarbonaceous material mixed with the ores of zinc in the perforatedgrate-bars, in consequence of the air being more evenly diffusedthroughout the ores by passing through the perforations of thegratebars. But to describe my furnace for manufacturing white oxide ofzinc from the ores of zinc or franklinite more particularly, I willrefer to the accompanying drawings, forming a part of this schedule, thesame letters of reference, wherever they occur, referring to the sameparts.

Figure 1 is a perspective View of the furnace. Fig. 2 is a cross-sectionof the same. Fig. 3 is a plan view of the base of the furnace, showingthe grate-bars.

Letter A is the case of the furnace, which may be made of brick, iron,or other material. The upper end of this case is contracted, so as toreflect the heat of the furnace back upon the ignited ores, and also toallow an exhaust-pipe to be attached thereto to col lect the oxide ofzinc as it passes off in the state of vapor in suitable receptacles forthat purpose, and well known in the process of manufacturing white oxideof zinc.

Letter Bis the base of the furnace, made air-tight, or as nearly so aspracticable, when the door 0 is closed up.

In the side of the air-chamber B is a pipe, D, having a throttle, E, init, which connects with a bellows-pipe, used for forcing the blast ofair into the furnace. On this base, at its junction with the case of thefurnace, are arranged a series of perforated grate-bars, F, set as neartogether as practicable, to prevent the air from escaping between themtoo freely instead of passing through the perfo- I rations of the gratebars. These bars are made in any of the usual forms suitable for thepurposes required. I prefer their being made rather heavier thangrate-bars are ordinarily made, so as to allow a greater number ofperforations in them than could be ob tained if made thin and the airpass between them; also for the purpose of making the perforationslarger at the under side of the bars than at the top, so as to admit theair more freely, and by its contraction diffuse it more thoroughlythroughout the mass of ore and coal.

Letters G, H, and I are three doors in the side of the furnace forfeeding the furnace and drawing out the cinder, 6c, from the furnacewhen to be cleaned out.

The operation of my furnace and the charging of the same for themanufacture of white oxide of zinc from ores of zinc or franklinite isby mixing the ores in a pulverized state with carbon pulverized or inlump, either in the form of anthracite coal, coke, or char coal, and inthis mixed state place them upon the grate-bars, or where-lump coal isused in combination with the mixed pulverized ores and carbonaceousinateriahthen to put on alayer of lump coal and then a course of thepulverized ore and carbon, and so on till the furnace is charged.Through this ignited mass of fuel and ore a blast of air, either hot orcold, is forced either in a continuous stream or in intermittent jets bymeans of a force-bellows, which fills the air-chamber with air, and asthe ash-door is scaled up the air is forced through the perforations ofthe grate-bars in a diffused and more even way than could be obtained ifallowed to pass between solid grate-bars to more perfectly promote thecombustion of the coal mixed with the ore, and thereby liberating thezinc in the form of vapor, which by contact with the oxygen of theatmosphere is' condensed into white oxide of zinc drawn off from the topof said furnace or lected in bags, which retain the oxide of zinc, butallow the gas to escape through them.

Having now described my invention and its operation, I will proceed tostate what I claim and desire to secure by Letters Patent of the UnitedStates.

Vhat I claim therefore isstove by an exhausting apparatus and col- Themanufacture of white oxide of zinc from ores of zinc or frankliniteprepared, substantially as above set forth, by means of a furnace havingperforated grate-bars, and an airohaniber underneath them, in which hotor cold blasts of air are forced to unite with the ignited mass of fuelin a diffused state by passing through the perforations of thegrate-bars to liberate the zinc in the form of vapor, in manner ofconstruction and mode of operation substantially as set forth.

JOHN E. BURROVVS. XVitn esses:

CHARLES L. BARRITT, WILLIAM C. SQUIER.

